


A Little Trouble

by DaniJayNel



Category: Shingeki no Kyojin | Attack on Titan
Genre: AU, Demon Ymir, F/F, Human historia, Oneshot, sunday prompt challenge
Language: English
Status: Completed
Published: 2019-07-14
Updated: 2019-07-14
Packaged: 2020-06-28 08:04:23
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,571
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/19808140
Author URL: https://archiveofourown.org/users/DaniJayNel/pseuds/DaniJayNel
Summary: With the intent of getting revenge on the kids that bully her, Historia decides to summon an ancient, powerful demon to do the deed for her. What she doesn't expect is for the Demon Lord Ymir to just be a demon teenager, and for her to be almost powerless due to the loss of magic in their worlds. When Ymir can't return to her world, she and Historia make a deal: Historia will help Ymir regain her energy until she can leave, and in return Ymir will help her get her revenge. It's a win-win. Except that Ymir looks like trouble, but Historia is definitely in the mood for some chaos.





	A Little Trouble

Their mocking words still pierced Historia’s ears as she stepped into the abandoned church. Its steps crumbled underneath her feet, but she knew to keep her balance. Inside the wooden pews were already rotten and barely recognizable. The once beautiful floor was littered with sand, leaves and various plastic objects; condoms, bottles, lighters, cigarette butts. A lot of kids came here to do mostly sinful things, but Historia knew the perfect time to come here herself, when she would be entirely alone.

To do this, she needed to make sure no one else saw her.

She listened to her own footsteps echo around the empty room as she approached the damaged podium, where she imagined a pudgy, balding white man had once stood, giving his sermons. Where was god now? Certainly not within these walls.

The windows were all broken, letting in late afternoon sun that spilled warmly across the dirty floor. Maybe the windows had been beautiful once, too. Historia paused in front of the podium and stared at the giant window frame, where a stunning stained-glass image of some saint had stared down at the gathered followers. It was now just an empty, gaping hole. Behind the church was an open field, so no one could see Historia here, even through the open window frame.

From her school bag, Historia withdrew an ancient, black book. She cradled it protectively to her chest, then pulled out the rest of the items she would need. With a bag of salt, she drew a complicated ancient symbol that meant _female vengeance_ , then positioned her red candles at every end of the six points. In the centre she placed the book, open on the page she would need. Historia had been imagining this moment for months.

She was the youngest of six kids, but she was also somewhat of a bastard. She had lost her birth mother very early on, and had gone to live with her biological father, but he hadn’t been interested in her. For all of her life, she had been living in boarding schools. Whenever she did return home, she always felt like a nuisance. Her siblings were alright, but they were more like strangers to her and they treated her like a frightened animal, too afraid to get near her, like she would spook and run away.

School was… well, Historia hated it. She was the shortest girl in the school. People regularly mocked her for it, and though she hadn’t ever done anything to anyone at the school, she was ostracised and bullied. Maybe they had just sensed her meekness and decided she was a good target. Historia was always too afraid to fight back, because if her father got involved he wouldn’t care about the situation, only that she had once again disappointed him.

Living with depression in this environment was so difficult for her mental health, and Historia really battled to just get out of bed in the mornings. Until she met a boy named Reiner from the boy’s boarding school close by. He was the first one to be kind to her, and she thought that being friends with him was probably what having a proper brother felt like.

He gave her the _Black Book of Magicks_ , which he strongly believed in, and told her that she could summon a demon. At first, she had laughed in his face. They had been in his room, Reiner on the floor and her on his bed. The sun had bathed them warmly and his room had smelt like clean towels.

_“Don’t laugh like that! My mom swears by this book.”_

_“Your mom summons demons?”_

_“Not, like, all the time. This book has been in my family for years. My mom says we’re descendant from a long line of magic users. We don’t use it much anymore because life has become so much more convenient, so you don’t need to ask a demon to boil your water for you.” He grinned. “But you can totally still do it for revenge.”_

Historia had taken the book, despite her doubt, but that night she had a vivid dream, and when she woke, the book had moved itself to her desk, open on page 110— _Demon Lord Ymir._

The book said that Ymir was the start of the magic users, that she had used her own blood and given it to humans, allowing them to use the book to summon herself and fellow demons, as well as wield a small amount of magic around them in nature. Not many people still held the blood of Ymir, and the book stated that no one could do a summoning without the correct bloodline.

Historia had done a lot of research and traced her family back to the Fritz, the very first family gifted with Ymir’s blood. A lot of the information she had found called it Ymir’s Curse, but Historia thought it was awesome.

Using the lessons from the book, Historia had taught herself how to use magic. She could only do very simple things, like force a plant to grow rapidly and bloom. She could very briefly lift objects with her mind, and sometimes she could see things that would happen. That’s how she knew that she could summon Ymir.

Unfortunately, her newfound abilities were too weak for her to get back at her bullies. But she was confident that Ymir would be able to do it for her.

Historia waited for the sun to dip just right, then she lit the candles and started chanting the words from the summon. She hoped she was pronouncing it right, because no one spoke ancient Eldian anymore.

From the first word, Historia felt the power in the air around her. Darkness started to creep in from the shadows, approaching much too rapidly to be natural, and it was as if the sun was quickly hiding away. It unnerved her a little, but she kept on, speaking louder and faster, eager to get it over with, to summon the great Demon Lord Ymir.

She could feel it in her blood—her call to Ymir. It was warm and it flowed right through her, pulling from her and aiding her. She fell to one knee, her whole body shaking, but she kept on with the ritual, kept her hands spread out in front of her. A small cloud of black lifted from between the pages of the book, and then she watched in awed surprise as the cloud grew and grew, and then it formed the shape of a person.

Historia finished the summon, her words echoing around the church, bouncing back into her ears. Her voice sounded strange to her, almost possessed. The cloud simmered and coiled like it was fighting with itself, then it suddenly exploded outwards and Historia was thrown back from the force of it. She landed hard on her ass, but she scrambled onto her knees and lifted her eyes, and there standing before her, with glistening bronze skin and two massive horns, was Ymir.

She was glorious.

Ymir’s shifting golden eyes took her kneeling form in, then she looked about the room. Her expression went downward, lips frowning, eyes narrowing. She stepped out of the ritual symbol and onto the church floor, and then she made a disgruntled noise and her gaze levelled with Historia’s.

“You summoned me in such a dump?”

Historia stared, open mouthed. Her tongue was nearly stuck to the top of her mouth from how dry it was. She swallowed thickly and clenched her hands into fists. “I—I apologize, my lord!”

The demon sauntered forward. Historia couldn’t stop staring at her, at the hard lines of her muscles, the stiff points of her nipples. A tale swished behind her and at her back she had two black folded wings, and her horns were beautiful. She didn’t seem to care about her nudity, and Historia was too starstruck to care about it either.

“Your lord?” Ymir asked her, voice dripping with amusement. “I’m no lord.”

Historia swallowed again. “The book, it—”

“Is a lot of bullshit,” Ymir cut in, gaze darkening. She walked closer until she was standing right in front of her, then she dropped down. They were somewhat level. Historia’s heart started to race. “But it was correct in detailing my abilities. What is it you desire, little human?”

Historia’s mouth all but hung open. “Revenge,” she croaked out.

“Huh? Speak up, I can’t hear you. And close your damn mouth.”

Historia immediately did so, blushing. Ymir was very… strong-willed. “I want to get revenge on the kids that bully me at school,” she said, voice louder. She injected as much fake confidence as she could.

Ymir stared at her for a long, hard second. She suddenly reached out with long, clawed fingers and then cupped the side of Historia’s face. Historia gasped, body suddenly alight with power and euphoria. She felt Ymir looking into every memory and thought that she had, but she allowed it willingly. When Ymir was done, she released her hold but her frown dissolved.

“I can’t grant that wish, Historia,” she sighed sadly. She collapsed on the dirty floor and curled her tail around her waist.

Historia blinked. “Wait, why?”

Ymir opened her hand and created a small ball of light. “Well, you see… I don’t really have the power to do what you want me to.”

“But… the book, it said you’re the most powerful demon!”

Ymir gave her a pained smile. “Once upon a very good time. Not so much anymore. This world has lost a lot of its magic, but mine has even less. Our contracts with the humans have all expired, and I can only really do things like this.” She threw her hand up, sending the light up to the ceiling, scattering all about like a disco. The lights writhed and danced, and then slowly faded away until they were in the darkness again. “Party tricks.”

“But…” Historia stared at her, chest tightening. “But I thought.”

Ymir shrugged. “You had a good thought. I can’t help you, though. I’m sure you understand.” She stood then and dusted her tail off.

Historia watched, disappointment and sadness crashing into her, as Ymir returned to the symbol. The black cloud from before started to form, enveloping her feet.

“Next time, summon me in a bath or something.” She grinned, like she hadn’t just smashed Historia’s heart in her hand. “Or like, a MacDonald’s or something.”

The cloud wafted up, but paused at her knees and stayed there, coiling and moving. Ymir glanced down at it, eyes suddenly alarmed. Historia opened her mouth, but then the cloud receded and faded away, and Ymir still stood there.

“Well, shit,” Ymir cursed, still staring down at the book.

“What happened?”

Historia finally stood but she didn’t bother wiping the dirt from her pants. Ymir looked at her, and the brightness of her golden eyes shifted into a darkening red.

“It takes a tremendous amount of energy to travel dimensions,” she said tersely, face darkening. “I don’t have enough power to go back.” Angrily, she kicked the book away from her.

Historia’s first instinct was to run for the book, but she forced herself not to. Instead, she released a shaky exhale. “So what does that mean?”

“That I’m stuck here,” Ymir ground out. Suddenly her nakedness was making Historia flustered.

“Oh, well… Is there a way you could get back?”

Ymir walked over to her again, tail lazily swishing about. “There is one way,” she purred, voice suddenly husky. Historia’s heart sped up again when Ymir circled her, a finger trailing along her throat.

“If I can help you, I will,” she croaked. “But only if you help me first.”

Ymir paused. She stared down at Historia, tail slowly swaying back and forth. Historia thought that she would reject the offer—hell, part of Historia wondered if Ymir wouldn’t just kill her right there and then, for summoning her without warning and stranding her here. Instead, Ymir released a loud bark of laughter, and then she was so close that Historia could smell grass on her impossibly warm skin. Ymir’s lips caressed the shell of her ear.

“Deal, little human,” she purred hotly.

Historia’s head started to swim. Ymir’s hands trailed down her arms, fingers caressing the edges of her wrists. Every inch of skin Ymir touched felt like it was set on fire. Historia had a sudden realization and her face burnt red, but she straightened her spine with conviction, and when Ymir gave her a lifted brow of question, she swallowed.

“My body is yours, if that’s what you need.”

Ymir stared at her blankly. Her brows furrowed, then her eyes widened when she understood. Her laughter made Historia blush harder. “You think I need to sleep with you? I mean, that is one way to do it, but no. I won’t ask that of you, Historia.” She snickered and walked away, giving Historia some room to breathe.

“What do you need then?” she asked her, careful to keep any disappointment out of her voice.

“Time to recharge.”

A soft light enveloped her, and then Historia watched as Ymir shrunk a little. Her horns, tail and wings disappeared and her eyes turned from bright gold to a beautiful brown. When she approached again, she was still much taller, but clearly human. She also looked very young—eighteen, like Historia.

“Funny enough, in demon years I’m just a kid, too,” Ymir told her with a cheeky grin. Her voice sounded a little different, a bit lighter. It was still incredibly alluring. “So, I have the power of persuasion. Take me to this principle of yours. I’ll help you get back at those assholes, then you’ll give me lots of food and entertainment in return.”

Historia’s heart soared. The disappointment from earlier was completely gone, replaced by excitement and hope. “You’ll really help me?”

“Hell yeah.” Ymir grinned broadly, baring her teeth. Her fangs were slightly too sharp, but that wouldn’t be a problem if she didn’t show them too often. “I keep my promises. So, let’s seal it in blood.” She slashed a small line across her palm, then took hold of Historia’s hand. After a nod of consent, Ymir cut her palm too. They placed their hands together and Historia felt their instant bond.

“This—”

“We are now imprinted,” Ymir told her casually, giving her hand a squeeze. “We will be able to sense each other, wherever we are. If you’re in danger, I’ll know. If you get hurt, I get hurt.” She finally let go.

Historia stared at her hand. It was smeared in black blood, but the wound immediately sealed up in a small bellow of steam. She looked up and into Ymir’s youthful eyes. Her grin was too wide, too excited. It dawned on Historia then, that she had definitely summoned a mischievous, attractive teen demon. Historia had a feeling this was going to cost her a lot.

Ymir’s grin widened. Historia lifted her hand, not looking, and pulled the book back to her. When it slammed into her bloody hand, she exhaled in a rush. There was more power coursing through her body, too.

Whatever the cost, she could deal with it. Ymir’s eyes promised trouble, but Historia decided she was totally okay with that.

Everyone needed a little trouble in their life.


End file.
